29 October 2010
Construction of the Dulles Corridor Metrorail Extension project, which is being built near Washington, D.C., is moving forward above and below ground. Crews have made significant progress on the elevated guideway structure that will carry the Metrorail over I-495, the region's primary highway, as well as Tysons Corner, one of the area's most congested business and retail districts. At the same time, a 2400-foot tunnel is being built under the intersection of Route 123 and International Drive as the traffic continues through Tysons Corner, and as the businesses and residents are going about their daily routines.